Microwave assisted hydrothermal synthesis of magnetite based nanoparticles for hyperthermia therapy

Superparamagnetic iron oxide nanoparticles (SPIONs) have great potential in theranostic applications due to their biocompatibility and unique magnetic properties. Magnetic hyperthermia is a therapeutic procedure based on the... [ view full abstract ]

Superparamagnetic iron oxide nanoparticles (SPIONs) have great potential in theranostic applications due to their biocompatibility and unique magnetic properties. Magnetic hyperthermia is a therapeutic procedure based on the use of magnetic nanoparticles (MNPs) which activated by an externally applied AC magnetic field induces a temperature increase in tissues and organs where tumoral cells are present.
In this work new synthesis route for doped magnetite with potential application in hyperthermia treatment is presented. The main goal was to analyze the influence of magnetite doping on morphological, structural/magnetic properties and heating efficiency of synthesized MNPs.
Nanostructured spinel oxides of the formula MIIFe2O4 (MII=Fe2+, Zn2+, Mg2+ and Co2+) were prepared using two-stage procedure which include co-precipitation at room temperature accompanied by hydrothermal treatment in microwave field at 100°C. Structure of the samples was analyzed by the use of X-ray diffraction data. Particle size and their distributions were examined using transmission electron microscope images and ImageJ software. DC magnetization was measured by SQUID magnetometer. Heating abilities of MNPs were compared by calculating Specific Absorption Rate (SAR), and Intrinsic Loss Power (ILP), using DM100 Series device (nB nanoScale, Spain).
An analysis of X-ray diffraction patterns showed good embedding of ions (Mg, Zn, Co) into parent magnetite compound. Different broadening of X-ray diffraction lines pointed to crystallite size dependence of dopant concentration. From TEM images it is clear that particles are well defined with size between 10 and 20 nm depending on the sample chemical composition. Calculated SAR values in the range of 90-150 W/g for 252 kHz frequency in 200 G magnetic field, indicated that samples show good heating efficiency. Both SAR and magnetization values depends on dopant and its concentration.
The main conclusion is that examined magnetite based samples have sufficient heating efficiency to be potentially used in hyperthermia therapy. Future research will be focused on the using of different surface coatings to form more stable colloids.